The utilization of external cardiohemodynamic patient assessment, applying non-invasive stick-on contact patches to the mother's neck on either side and chest wall on either side, enables the practitioner to have information about the patient's cardiac function and vascular status beyond simply blood pressure and pulse. This information, once collected, should open the practitioner's eyes to better assess the patient's disease status and her response to therapy. We will use this information to compare the effectiveness of the two standard medications used for treatment of maternal high blood pressure.

Pregnant patients with severe acute hypertension due either to superimposed preeclampsia, severe preeclampsia or severe gestational hypertension will be randomized to receive either of two antihypertensive agents (hydralazine or labetalol). Just before drug administration and immediately thereafter impedance cardiography of the patient will be undertaken and the results analyzed relative to the cardiac profile and the drug administered to reduce the severe hypertension.

Inclusion Criteria:

• Nulliparous or parous patients with severe hypertension
• Singleton gestation
• Gestational age greater than 20 weeks

Exclusion Criteria:

• Multiple gestation
• Gestational age less than 20 weeks

Nulliparous or parous patients with severe hypertension, a singleton gestation, gestational age greater than 20 weeks along who are admitted to the Wiser Hospital for Women and Infants at the University of Mississippi Medical Center.